<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
    <meta charset="UTF-8" >
    <title>Title</title>
</head>
<body>
<!--将静态文件放入static中-->
<script type="text/javascript" th:src="@{jquery-3.5.1.js}"></script>
<script type="text/javascript">
    $(function (){
        alert($("#username").val());
    })
</script>
<input type="text" id="username" value="张三"/><br>
<br>
<img th:src="nuanuan.jpg"/><br>
</body>
</html>